Many provisions have been heretofore proposed with regard to the development of plastic film bags manufactured, for example, of film strips of polyethylene or the like. Some developments have been shown for bags and envelopes in general in U.S. Pat. Nos. 2,066,495; 2,131,575; 2,330,666; 2,991,001; 3,026,018; 3,203,621; 3,670,947; 3,990,627; and 4,415,087.
W. E. Swift in U.S. Pat. No. 2,066,495 reveals an envelope having correspondingly shaped areas of its seal flap and body coated with a dry- sealing adhesive. An apertured portion of the envelope body is disposed beween the adhesive areas to maintain the adhesive areas out of engagement. Sealing of the envelope is effected by pressing portions of the adhesive areas into contact through the apertured portion. In this arrangement, the flap is fabricated of a monolithic piece provided with the aforesaid apertures and there is further provided a cooperating adhesive on the envelope itself, which cooperating adhesive along with the first noted adhesive is of such a character that it will adhere upon non-moistened contact to the other adhesive, although it will not adhere to the material of which the envelope is made.
C. R. Whipple in U.S. Pat. No. 2,131,575 reveals an envelope which includes a pocket and a flap for closing the pocket which normally overlies a part of the rear wall of the envelope. Adjacent faces on the flap and on the rear wall of the envelope have complementary areas coated with an adhesive of the type which will adhere to itself upon the application of pressure alone, but will not adhere to the uncoated parts. The adhesive coating on at least one of the parts has uncoated areas adjacent to the coated areas which are disposed out of the normal plane of the coated areas for normally maintaining the coated areas on the two parts in spaced relation. The coated areas on the respective parts are adapted to be brought into adhering by the application of pressure to the overlying coated areas.
In U.S. Pat. No. 2,330,666, E. B. Berkowitz reveals a quick opening envelope formed of fibrous material including a body portion and a seal flap portion extending along an opening in said body portion through which contents of the envelope may be emptied. A gum repellent coating on one of the portions is provided, contacting the other portion when the seal flap portion is in sealed position. The portion provided with the gum repellent coating has restricted uncoated sealing spaces within the coated area. Gum between the portions for effecting seal at the restricted spaces is provided. Substantially arcuate cutting edges are provided by the coating on sides of the sealing space nearest the opening for severing any fibers which are embedded in the gum when the flap portion is pulled loose while opening the envelope.
W.L. Hughes in U.S. Pat. No. 2,991,001 discloses a resealable container. This container has a body portion and an entrance at one end of the same. A resealing arrangement is provided which overlies a peripheral resealing path defined by perforations in the container. Further included is a tear strip adjacent the exterior or the resealing path and protruding into the container. A pressure-sensitive tape overlies the tear strip and the resealing path. The tear strip is disengageable from the tape to tear and remove the resealing path and thus expose pressure sensitive portions of the tape for mutual adhesion and resealing of the container.
E. Stratton reveals in U.S. Pat. No. 3,026,018 envelopes having gummed flaps formed with tape. More particularly, an envelope is provided which includes a front and a back joined at their peripheral edges to form an envelope pocket. A flap is hinged to the front along a fold line. This flap is swingable above the fold line to close the envelope pocket. Longitudinally projecting portions formed integrally with the bag and positioned at opposite ends of the fold line are provided. The longitudinally projecting portions extend across the lines of fold between the front and the flap, and are in adhering relationship to the flap in order to strengthen the envelope at the opposite ends of the line of fold.
D. Wright in U.S. Pat. No. 3,203,621 reveals a bagtop closure made of paper, folded along a crease to form two panels. Each of these panels has a substantial portion of its inside surface coated with an adhesive composition such as, for example, water-soluble adhesive compositions and heat sensitive thermoplastic adhesive compositions. The adhesive coating on one of the panels is rendered ineffective except for a small area by a patterned application of a superimposed coating of a permanent masking agent. In this arrangement, an attached tab depends from the bottom edge of the masked panel and employs an adherent coating of a pressure-sensitive adhesive composition.
A hanger bag with a flap closure is shown by A. Tangredi et al in U.S. Pat. No. 3,670,947. This hanger bag is formed from a single, elongated sheet of flexible thermoplastic film by cutting a series of spaced-apart notches in one of the longitudinal edges of the film. The distance between the notches is the desired width of the finished bag. The opposite longitudinal end of the sheet is doubled back to the desired height of the finished bag. The notched edge is folded over the opposite edges and a hanger or handle member is heat sealed to the upper folded-over edge between the spaced-apart notches. Thereafter there is effected the step of heat sealing and severing the folded film transversely, with the heat seal passing through the notch whereby a finished bag is formed. This arrangement employs a pressure sensitive tape to keep the flap secured. The flap is itself in the form of a monolithic structure.
In U.S. Pat. No. 3,990,627, R. Olson discloses an adhesive closure for bags, including an adhesive stripe located adjacent the open mouth portion of the bag. The adhesive stripe is covered until ready for use by the upper portion of the bag's front wall whereby upward displacement of the front wall exposes the adhesive stripe for sealing the upper portion of the bag walls together.
W. Clayton et al reveal in U.S. Pat. No. 4,415,087 an improved adhesive system for forming releasable channel closures for flexible bags. The adhesive system includes a layer of hot melt adhesive over which a thin second layer of a liquid-based adhesive such as a water-based pressure sensitive acrylate is applied.
None of the aforegoing patents reveal the provision of a flap portion consisting of two entirely separate sections, separated by a gap which is bridged by a tape bearing thereupon a pressure-responsive adhesive as will be discussed in further detail hereinbelow.